| [presence of endamoeba histolytica in rats in buenos aires]. | | 1951 | 14853814 |
| [chloroquine in the treatment of intestinal ulcerations from endamoeba histolytica]. | | 1951 | 14858095 |
| evidence of direct amebicidal action of agents tested in vitro against endamoeba histolytica. | | 1951 | 14861730 |
| [case reports of bronchitis caused by entamoeba histolytica]. | | 1951 | 14863351 |
| [presence of endamoeba histolytica in rats in buenos aires]. | | 1951 | 14864334 |
| role of bacteria on the growth of entamoeba histolytica; a preliminary note on studies in relation to an unusual strain of entamoeba histolytica. part i, the growth characteristics of e. histolytica. | | 1951 | 14868986 |
| role of bacteria on the growth of entamoeba histolytica; a preliminary note on studies in relation to an unusual strain of entamoeba histolytica. part ii. the effects on the growth and viability of e. histolytica on inhibition of the original bacteria and on addition of new bacteria. | | 1951 | 14868987 |
| role of bacteria on the growth of entamoeba histolytica; a preliminary note on studies in relation to an unusual strain of entamoeba histolytica. part iii. detection of the enzymes in the culture media. | | 1951 | 14868988 |
| an entamoeba histolytica line/sine pair inserts at common target sites cleaved by the restriction enzyme-like line-encoded endonuclease. | the non-long-terminal-repeat (non-ltr) retrotransposons (also called long interspersed repetitive elements [lines]) are among the oldest retroelements. here we describe the properties of such an element from a primitive protozoan parasite, entamoeba histolytica, that infects the human gut. this 4.8-kb element, called ehline1, is present in about 140 copies dispersed throughout the genome. the element belongs to the r4 clade of non-ltr elements. it has a centrally located reverse transcriptase do ... | 2004 | 14871947 |
| the duration and epidemiological significance of entamoeba histolytica infections in rats. | | 1951 | 14901446 |
| researches on the intestinal protozoa of monkeys and man. xii. bacterial factors influencing the life history of entamoeba histolytica in cultures. | | 1952 | 14929556 |
| experimental production of pure mixed strains of entamoeba histolytica. | | 1952 | 14929557 |
| the feed habits of entamoeba histolytica in its commensal phase. | | 1952 | 14929558 |
| the experimental infection of macaca mulatta with human strains of entamoeba histolytica. | | 1952 | 14933691 |
| [clinical importance of the intestinal parasites of man with special consideration of entamoeba histolytica]. | | 1951 | 14936750 |
| the stool examination reports amoeba cysts: should you treat in the face of over diagnosis and lack of specificity of light microscopy? | amoebiasis is a common clinical diagnosis in tropical settings and clinicians continue to treat asymptomatic carriers diagnosed by light microscopy. a minority of carriers, however, are infected with entamoeba histolytica and the remaining with the non-pathogenic entamoeba dispar. we compared the diagnostic results of 298 asymptomatic residents of aracaju, brazil, obtained by different diagnostic methods, and ascertained their clinical symptoms, to highlight the implications for practitioners. f ... | 2004 | 14959971 |
| origins, lineage-specific expansions, and multiple losses of tyrosine kinases in eukaryotes. | tyrosine kinases are important components of metazoan signaling pathways, and their mutant forms are implicated in various malignancies. searching the sequences from the genomes of 28 eukaryotes and the genbank, we found tyrosine kinases not only in metazoans but also in the green algae chlamydomonas reinhardtii, the potato late blight pathogen phytophthora infestans, and the protozoan pathogen entamoeba histolytica, contrary to the current view that tyrosine kinases are animal-specific. based o ... | 2004 | 14963097 |
| amoebiasis distribution in the past: first steps using an immunoassay technique. | the identification of parasites in ancient human faeces is compromised by differential preservation of identifiable parasite structures. however, protein molecules can survive the damage of the environment and can be detected even after centuries. in this paper it is shown that is possible to detect copro-antigen of entamoeba histolytica in historic and prehistoric human faecal remains, using a commercially available enzyme immunoassay (elisa) kit. the kit uses monoclonal antibody-peroxidase con ... | 2004 | 14964807 |
| cryopreservation of protozoan parasites. | conventional methods for the propagation and preservation of parasites in vivo or in vitro have some limitations, including the need for labor, initial isolation and loss of strains, bacterial, and fungal contamination, and changes in the original biological and metabolic characteristics. all these disadvantages are considerably reduced by cryopreservation. in this study, we examined the effects of various freezing conditions on the survival of several protozoan parasites after cryopreservation. ... | 2004 | 14969677 |
| solution structure of the pore-forming protein of entamoeba histolytica. | amoebapore a is a 77-residue protein from the protozoan parasite and human pathogen entamoeba histolytica. amoebapores lyse both bacteria and eukaryotic cells by pore formation and play a pivotal role in the destruction of host tissues during amoebiasis, one of the most life-threatening parasitic diseases. amoebapore a belongs to the superfamily of saposin-like proteins that are characterized by a conserved disulfide bond pattern and a fold consisting of five helices. membrane-permeabilizing eff ... | 2004 | 14970207 |
| present characteristics of symptomatic entamoeba histolytica infection in the big cities of japan. | medical records, for 2000 and 2001, of symptomatic amoebic patients who were treated at our hospitals in tokyo, yokohama and osaka were studied retrospectively for the purpose of gathering epidemiological data on symptomatic entamoeba histolytica infection. a total of 58 patients were treated. fifty-five of them were male, and 96% of the male patients were japanese. the mean age of patients was 44.9 years old, and 91% of patients contracted the disease in japan. fifty-six per cent of the male pa ... | 2004 | 14979590 |
| in vitro and in vivo interaction of entamoeba histolytica gal/galnac lectin with various target cells: an immunocytochemical analysis. | the gal/galnac lectin of entamoeba histolytica trophozoites plays an important role in adhesion. the distribution and final destiny of the lectin during the interaction with host cells are poorly understood. using monoclonal and polyclonal antibodies against the lectin we studied by immunocytochemistry the in vitro and in vivo interaction of e. histolytica trophozoites with human and hamster hepatocytes. we also analyzed the presence and distribution of the lectin in a mouse model of intestinal ... | 2004 | 14984834 |
| a description of the mei2-like protein family; structure, phylogenetic distribution and biological context. | the schizosaccharomyces pombe mei2 gene encodes an rna recognition motif (rrm) protein that stimulates meiosis upon binding a specific non-coding rna and subsequent accumulation in a "mei2-dot" in the nucleus. we present here the first systematic characterization of the family of proteins with characteristic mei2-like amino acid sequences. mei2-like proteins are an ancient eukaryotic protein family with three identifiable rrms. the c-terminal rrm (rrm3) is unique to mei2-like proteins and is the ... | 2004 | 14986133 |
| molecular-based diagnosis of entamoeba histolytica infection. | | 1999 | 14987356 |
| effect of human milk and colostrum on entamoeba histolytica. | many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. in the present study, we investigated the effect of colostrum and mature human milk on e. histolytica parasites in vitro. | 2004 | 14991951 |
| determination of the prevalence of entamoeba histolytica and e. dispar in the pernambuco state of northeastern brazil by a polymerase chain reaction. | previous studies using methods varying from traditional serologic tests to molecular biology techniques have shown that in northeastern brazil, entamoeba dispar was more prevalent than e. histolytica. in this study, the prevalence was established by using e. histolytica stool antigen detection kits and a polymerase chain reaction (pcr) with genomic dna extracted from cultured trophozoites in all four-nuclei, amoeba-positive samples from a population living in macaparana in northeastern brazil. a ... | 2004 | 14993636 |
| ameboma mimicking carcinoma of the cecum: case report. | | 2004 | 14997156 |
| the use of real-time pcr to identify entamoeba histolytica and e. dispar infections in prisoners and primary-school children in ethiopia. | in ethiopia, it is generally unknown what proportion of the amoebic infections commonly found, by microscopy, in humans are caused by non-invasive entamoeba dispar rather than the potentially invasive e. histolytica. faecal samples were therefore collected from 363 primary-school students and 409 prisoners from various regions of ethiopia. each of these samples was checked for entamoeba infection by the microscopical examination of formol-ether concentrates. dna was then extracted from the 213 s ... | 2004 | 15000730 |
| evaluation of recombinant fragments of entamoeba histolytica gal/galnac lectin intermediate subunit for serodiagnosis of amebiasis. | we have recently identified a 150-kda surface antigen of entamoeba histolytica as an intermediate subunit (igl) of galactose- and n-acetyl-d-galactosamine-inhibitable lectin, which is a cysteine-rich protein consisting of 1,101 amino acids (aa) and containing multiple cxxc motifs in amino acid sequences. in the present study, full-length igl except for the signal sequences (aa 14 to 1088) and three fragments of igl-the n-terminal part (aa 14 to 382), the middle part (aa 294 to 753), and the c-te ... | 2004 | 15004055 |
| simultaneous detection of entamoeba histolytica, giardia lamblia, and cryptosporidium parvum in fecal samples by using multiplex real-time pcr. | entamoeba histolytica, giardia lamblia, and cryptosporidium are three of the most important diarrhea-causing parasitic protozoa. for many years, microscopic examination of stool samples has been considered to be the "gold standard" for diagnosis of e. histolytica, g. lamblia, and c. parvum infections. recently, more specific and sensitive alternative methods (pcr, enzyme-linked immunosorbent assay, and direct fluorescent-antibody assay) have been introduced for all three of these parasitic infec ... | 2004 | 15004079 |
| the ehadh112 recombinant polypeptide inhibits cell destruction and liver abscess formation by entamoeba histolytica trophozoites. | the entamoeba histolytica ehcpadh complex, formed by a cysteine proteinase (ehcp112) and an adhesin (ehadh112), is involved in adherence, phagocytosis and cytolysis. this makes this complex an attractive candidate as a vaccine against amoebiasis. here, we produced the recombinant polypeptide ehadh243, which includes the adherence epitope detected by a monoclonal antibody against the ehcpadh complex. ehadh243 was purified, and the effect of the polypeptide on in vitro and in vivo virulence was st ... | 2004 | 15009028 |
| purification and biochemical characterisation of a membrane-bound alpha-glucosidase from the parasite entamoeba histolytica. | an alpha-glucosidase was solubilised from a mixed membrane fraction of entamoeba histolytica and purified to homogeneity by a two-step procedure consisting of ion exchange chromatography in a mono q column and affinity chromatography in concanavalin a-sepharose. although the enzyme failed to bind the lectin, this step rendered a homogenous and more stable enzyme preparation that resolved into a single polypeptide of 55 kda after sds-page. as measured with 4-methylumbelliferyl-alpha-d-glucopyrano ... | 2004 | 15013735 |
| entamoeba histolytica: kinetic and molecular evidence of a previously unidentified pyruvate kinase. | we report the kinetic characterization of a previously unidentified pyruvate kinase (pk) activity in extracts from entamoeba histolytica trophozoites. this activity was about 74% of the activity of pyruvate phosphate dikinase. ehpk differed from most pks in that its ph optimum was 5.5-6.5 and was inhibited by high pep concentrations (1-5mm); these are concentrations at which pk is usually assayed. the optimal temperature was above 40 degrees c with negligible activity below 20 degrees c. ehpk ex ... | 2004 | 15013784 |
| [a diagnostic approach to hepatic abscess]. | the non invasive diagnosis of amebic liver abscess allows the use of empirical therapy without the requirement of invasive diagnostic procedures. | 2003 | 15022404 |
| [parasitic diarrhea in children]. | in many areas, entamoeba histolytica and entamoeba dispar are found together and their microscopic appearance is identical. biochemical tests which can show cell wall differences are often falsely negative and the only possible way is to treat with metronidazole when amoebiasis is suspected. in case of clinical failure of metronidazole, a bacterial diarrhea is frequently found. giardia is an other protozoa frequently found in stools of children in endemic areas. diarrheas due to giardia are poss ... | 2003 | 15022781 |
| common intestinal parasites. | intestinal parasites cause significant morbidity and mortality. diseases caused by enterobius vermicularis, giardia lamblia, ancylostoma duodenale, necator americanus, and entamoeba histolytica occur in the united states. e. vermicularis, or pinworm, causes irritation and sleep disturbances. diagnosis can be made using the "cellophane tape test." treatment includes mebendazole and household sanitation. giardia causes nausea, vomiting, malabsorption, diarrhea, and weight loss. stool ova and paras ... | 2004 | 15023017 |
| diabetes and amoebiasis: a high risk encounter. | amoebiasis is the second most common parasitic disease worldwide. it occurs mainly in developing countries. a high percentage of people in countries where it is endemic are asymptomatic carriers. it results in severe disease that can be fatal in rare cases. diabetics are at increased risk of exposure as travel to countries where it is endemic becomes more frequent, as indicated by the present case. this patient suffered from amoebiasis that produced an amoeboma which is most rare in cases of col ... | 2004 | 15029104 |
| the iron-sulfur cluster assembly genes iscs and iscu of entamoeba histolytica were acquired by horizontal gene transfer. | iron-sulfur (fes) proteins are present in all living organisms and play important roles in electron transport and metalloenzyme catalysis. the maturation of fes proteins in eukaryotes is an essential function of mitochondria, but little is known about this process in amitochondriate eukaryotes. here we report on the identification and analysis of two genes encoding critical fes cluster (isc) biosynthetic proteins from the amitochondriate human pathogen entamoeba histolytica. | 2004 | 15040816 |
| [epidemiological, social, and sanitary aspects in an area of the rio negro, state of amazonas, with special reference to intestinal parasites and chagas' disease]. | a cross-sectional study was carried out on the residents of one in every four dwellings in the town of barcelos (in the northern part of the state of amazonas, on the right bank of the rio negro, 490 kilometers from manaus by river), in order to evaluate social and sanitary conditions and specific indicators for intestinal parasites and chagas' infection. during the survey, two questionnaires were applied, a household one to evaluate social and sanitary aspects, and an individual one, for social ... | 2004 | 15042222 |
| cytogenetic study of metronidazole and three metronidazole analogues in cultured human lymphocytes with and without metabolic activation. | metronidazole (mtz) and other nitroimidazole derivatives have been extensively used to treat infections caused by protozoa and anaerobic bacteria. however, the need for new derivatives with similar therapeutic activity but lower toxicity to human beings prevails. on this purpose, three metronidazole analogues were synthesized, namely: 1-(p-methylphenacyl)-2-methyl-4-nitro imidazole (cpme), 1-(p-methoxyphenacyl)-2-methyl-4-nitroimidazole (cpmeo), and 1-(p-fluorphenacyl)-2-methyl-4-nitroimidazole ... | 2004 | 15046779 |
| consumption of l-arginine mediated by entamoeba histolytica l-arginase (eharg) inhibits amoebicidal activity and nitric oxide production by activated macrophages. | in this study we discuss the cloning and expression of entamoeba histolytica arginase (eharg), an enzyme that catalyses the hydrolysis of l-arginine to l-ornithine and urea. l-norvaline, a competitive inhibitor of e. histolytica l-arginase, inhibits the growth of the parasite, which suggests that the catabolism of l-arginine mediated by eharg is essential. nitric oxide (no) is an antimicrobial agent that inhibits some key enzymes in the metabolism of entamoeba histolytica. no is synthesized by a ... | 2003 | 15053781 |
| foodborne and waterborne parasites. | more than 72 species of protozoan and helminth parasites can reach humans by food and water, and most of these infections are zoonoses. some parasites show a cosmopolitan distribution, others a more restricted distribution due to their complex life cycles, which need the presence of one or more intermediate hosts. of this large number of pathogens, only toxoplasma gondii can be transmitted to humans by two different ways, i.e., by cysts present in infected meat and by oocysts contaminating food ... | 2003 | 15058817 |
| environmental contamination with protozoan parasite infective stages: biology and risk assessment. | in the present paper some aspects of the biology and various factors influencing the potential for environmental contamination with protozoan parasites infective stages implicated in water and foodborne diseases are described. the major protozoan species that affect humans are entamoeba histolytica, acanthamoeba sp., neagleria sp. giardia intestinalis, cryptosporidium parvum, cyclospora cayetanensis, toxoplasma gondii, isospora/sarcocystis sp. encephalitozoom intestinals and enterocytozoon biene ... | 2003 | 15058818 |
| parasite-specific antibody and cytokine profiles in newborns from plasmodium falciparum and entamoeba histolytica/dispar-infected mothers. | passage of parasites and their antigens across the placenta occurs with metazoan as well as protozoan parasites, and this study addressed to which extent exposure to and infection of mothers with plasmodium spp. and entamoeba histolytica/dispar has sensitized their offspring for parasite-specific immune responses. while at delivery none of the mothers presented with an acute malaria attack, 42% were seropositive for p. falciparum. in half of the mothers cysts of e. histolytica/dispar were detect ... | 2004 | 15059189 |
| entamoeba histolytica trophozoites transfer lipophosphopeptidoglycans to enteric cell layers. | transfer of antigens frequently follows adhesion of protozoan parasites to host cells. we were interested in such transfer from the entamoeba surface to enterocytes following adhesion of trophozoites. therefore, cocultures of enterocytes in vitro and ex vivo with entamoeba histolytica (strain hm-1:imss) or entamoeba dispar (strain saw760) trophozoites were processed for immunocytochemistry. the eh5 monoclonal antibody against amoebic proteophosphoglycans marked a dotted pattern on the apical sid ... | 2004 | 15064119 |
| accurate diagnosis is essential for amebiasis. | | 2004 | 15069733 |
| indirect determination of nitric oxide production by reduction of nitrate with a freeze-thawing-resistant nitrate reductase from escherichia coli mc1061. | preparation of a nitrate reductase lysate of escherichia coli mc1061 to measure nitrate and nitrite in biologic fluids is described. to obtain the crude bacterial lysate containing nitrate reductase activity, e. coli mc1061 was subjected to 16-20 freeze-thawing cycles, from -70 to 60 degrees c, until nitrite reductase activity was < or = 25%. nitrate reductase activity was detected mainly in the crude preparation. to validate the nitrate reduction procedure, standard nitrate solutions (1.6-100 m ... | 2004 | 15081902 |
| limitation of communal latrines in changing the prevalence of parasites and diarrhoeal attack rate in dhaka peri-urban slums. | a study of the effects of communal latrines on diarrhoeal incidence and parasite prevalence rates was conducted in 1983 at tongi, which had five communal oxfam latrines with a manual flushing system for 924 people; and at kalsi, which had 39 open fit latrines for 823 people. inhabitants' stool samples were tested initially and also after twelve months to see the reinfection rates. all inhabitants were dewormed with pyrantel, and were visited weekly to obtain diarrhoea histories. in both communit ... | 1987 | 15092706 |
| membrane lipid composition protects entamoeba histolytica from self-destruction by its pore-forming toxins. | the protozoan parasite and human pathogen entamoeba histolytica is protected against killing by its own lytic effector proteins. amoebae withstand doses of amoebapores, their pore-forming polypeptides, that readily kill human jurkat t cells. moreover, the polypeptides do not bind to the amoebic surface membrane as evidenced by using fluorescently labelled amoebapores and confocal laser microscopy. experiments employing liposomes as a minimalistic membrane system and the major isoform amoebapore ... | 2004 | 15094050 |
| zoonotic intestinal parasites in papio anubis (baboon) and cercopithecus aethiops (vervet) from four localities in ethiopia. | a total of 59 faecal samples from ranging papio anubis (baboons) and another 41 from cercopithecus aethiops (vervet) from the rift valley areas of ethiopia were microscopically examined to determine the prevalence and species of major gastro-intestinal parasites of zoonotic importance. faecal smears were prepared from fresh faecal samples, stained using modified ziehl-neelsen method and microscopically examined. about 3 gm of the dropping was also preserved separately in clean and properly label ... | 2004 | 15099809 |
| rna interference in protozoan parasites. | rna interference or rnai is defined as the mechanism through which gene-specific, double-stranded rna (dsrna) triggers degradation of homologous transcripts. besides providing an invaluable tool to downregulate gene expression in a variety of organisms, it is now evident that rnai extends its tentacles into both the nucleus and the cytoplasm and is involved in a variety of gene silencing phenomena. here we review the current status of rnai in protozoan parasites that cause diseases of considerab ... | 2004 | 15104593 |
| stereotypic and specific elements of the human colonic response to entamoeba histolytica and shigella flexneri. | the clinical presentations of bacillary dysentery caused by shigella, and amoebic dysentery caused by the protozoan parasite entamoeba histolytica, can be indistinguishable, with both organisms causing colonic mucosal damage and ulceration. however, the two organisms are quite distinct, and have very different pathogenic mechanisms. this raises the fundamental question of whether the similar clinical manifestations reflect a stereotypic response of the human gut to mucosal injury, or whether the ... | 2004 | 15104595 |
| involvement of protein kinases on the process of erythrophagocytis by entamoeba histolytica. | erythrophagocytic capacity of trophozoites of entamoeba histolytica is considered a factor in the virulence of this pathogenic protozoan. we present evidence showing that such activity resembles the ingestion of microorganisms by highly differentiated phagocytic cells, such as macrophages. previous treatment of the trophozoites with genistein or tyrphostin, inhibitors of tyrosine protein kinases, with staurosporine, a protein kinase c inhibitor, and wortmannin, a fungal metabolite that inhibits ... | 2004 | 15109979 |
| a unique rab gtpase, ehraba, of entamoeba histolytica, localizes to the leading edge of motile cells. | entamoeba histolytica, an enteric protozoan parasite, infects 10% of the world's population leading to 50 million cases of invasive amoebiasis annually. parasite vesicle trafficking and motility, which relies on vesicle trafficking to deliver membrane and membrane components to the leading edge, are important for virulence however little is known about the molecular mechanisms regulating these functions. since rab gtpases are known modulators of vesicle trafficking we have characterized a rab gt ... | 2004 | 15110460 |
| synthesis, characterization and in vitro antiamoebic activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones and their palladium (ii) and ruthenium (ii) complexes. | synthesis of new palladium(ii) and ruthenium(ii) complexes of the type, [pd(l)cl(2)] and [ru(eta(4)-c(8)h(12))(l)cl(2)] [where, l = thiosemicarbazones derived from 5-nitrothiophene-2-carboxaldehyde and cycloalkylaminothiocarbonyl hydrazines] have been isolated by the reaction of [pd(dmso)(2)cl(2)] and [ru(eta(4)-c(8)h(12))(ch(3)cn)(2)cl(2)] with 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones. the spectral data revealed that the thiosemicarbazones act as bidentate ligands, making use of thi ... | 2004 | 15110972 |
| short communication: misleading microscopy in amoebiasis. | high prevalences of intestinal amoebiasis are commonly reported by microscopy in ethiopia. in order to confirm the actual occurrence of entamoeba histolytica we collected 108 stool specimens from different hospitals & health centers from patients in whom haematophagous trophozoites were believed to be found. we detected only a single e. histolytica case while 77 (71.3%) were e. dispar and the remaining 30 samples were negative for both species by real-time pcr based on the small subunit ribosoma ... | 2004 | 15117312 |
| intestinal parasitic infections in hiv/aids and hiv seronegative individuals in a teaching hospital, ethiopia. | the magnitude of intestinal parasitic infection in human immunodeficiency virus (hiv) /aids patients requires careful consideration in the developing world. however, there have been very few studies addressing this issue in ethiopia. this study was conducted to determine the prevalence of intestinal parasitic infection in hiv/aids patients at jimma hospital, southwest ethiopia, between january and february 2002. stool specimens from hiv/aids patients and control groups were screened for intestin ... | 2004 | 15118206 |
| effects of piper longum fruit, piper sarmentosum root and quercus infectoria nut gall on caecal amoebiasis in mice. | the anti-amoebic effects of crude methanol extracts of piper longum fruit, piper sarmentosum root and quercus infectoria nut gall against entamoeba histolytica infecting the caecum of mice were studied. caecal amoebiasis in mice was induced by injection of entamoeba histolytica trophozoites directly into the caecum. the mice were then treated orally with the extract, a standard drug (metronidazole), or vehicle p.o. for five consecutive days, beginning 24 h after the infection and were examined o ... | 2004 | 15120461 |
| using ancestral sequences to uncover potential gene homologues. | gene homologues between distantly related species can be difficult to identify. we test the idea that inferred ancestral sequences could aid in finding gene homologues. ancestral sequences are inferred by aligning gene homologues on a known tree and estimating the most likely amino acid for each position at each node in that tree. blast(r) and hmmer are used separately and together with ancestral sequences to search the genome sequence databases of encephalitozoon cuniculi, entamoeba histolytica ... | 2003 | 15130821 |
| mitosomes of entamoeba histolytica are abundant mitochondrion-related remnant organelles that lack a detectable organellar genome. | the existence of mitochondrion-related relict organelles (mitosomes) in the amitochondrial human pathogen entamoeba histolytica and the detection of extranuclear dna-containing cytoplasmic structures (ehkos) has led to the suggestion that a remnant genome from the original mitochondrial endosymbiont might have been retained in this organism. this study reports on the mutually exclusive distribution of cpn60 and extranuclear dna in e. histolytica and on the distribution of cpn60-containing mitoso ... | 2004 | 15133087 |
| expression in fibroblasts and in live animals of entamoeba histolytica polypeptides ehcp112 and ehadh112. | ehcpadh is an immunogenic, heterodimeric protein that is formed by ehcp112 (cysteine protease) and ehadh112 (adhesin), polypeptides involved in entamoeba histolytica's cytopathic effect, target-cell adherence and phagocytosis. the ehcpadh complex is located in the plasma membrane and cytoplasmic vacuoles. here, the independent expression of ehcp112 and ehadh112 in fibroblasts and hamsters was analysed. also investigated was the immunological response in animals independently inoculated with plas ... | 2004 | 15133088 |
| microbial contamination of drinking water and disease outcomes in developing regions. | drinking water is a major source of microbial pathogens in developing regions, although poor sanitation and food sources are integral to enteric pathogen exposure. gastrointestinal disease outcomes are also more severe, due to under-nutrition and lack of intervention strategies in these regions. poor water quality, sanitation and hygiene account for some 1.7 million deaths a year world-wide (3.1% of all deaths and 3.7% of all daly's), mainly through infectious diarrhoea. nine out of 10 such deat ... | 2004 | 15138046 |
| contact of entamoeba histolytica with baby hamster kidney-21 (bhk-21) cell line on cysteine proteinase activity. | entamoeba histolytica, the causative agent of amoebiasis and amoebic liver abscess, lyses host cells by direct contact using surface lectins and releases cysteine proteinase (cp). virulence of e. histolytica is directly related to activity of its cp. the relationship of cp activity and cytotoxicity has not been established. the present study was carried out to explore the events following contact of e. histolytica with target cells. | 2004 | 15147121 |
| entamoeba histolytica alcohol dehydrogenase 2 (ehadh2) as a target for anti-amoebic agents. | the current use of metronidazole as an anti-amoebic agent causes significant side-effects. the purpose of this study was to identify alternative compounds with which to treat amoebiasis. | 2004 | 15150165 |
| an anti-inflammatory oligopeptide produced by entamoeba histolytica down-regulates the expression of pro-inflammatory chemokines. | axenically grown entamoeba histolytica produces a pentapeptide (met-gln-cys-asn-ser) with anti-inflammatory properties that, among others, inhibits the in vitro and in vivo locomotion of human monocytes, sparing polymorphonuclear leucocytes from this effect [hence the name originally given. monocyte locomotion inhibitory factor (mlif)]. a synthetic construct of this peptide displays the same effects as the native material. we now added mlif to resting and pma-stimulated cells of a human monocyte ... | 2003 | 15157024 |
| human amoebic hepatic abscess: in situ interactions between trophozoites, macrophages, neutrophils and t cells. | amoebic liver abscesses (ala) are the most frequent and severe extraintestinal clinical presentations of amoebiasis. during the early establishment of amoebae in the liver parenchyma, as well as during the extension of the tissue necrosis, parasites interact with the parenchymal liver cells and, as a consequence of these interactions, hepatocytes can be destroyed and host immune cells can become activated. however, little is known about the nature of these interactions in the liver or about the ... | 2003 | 15157027 |
| trypanothione reductase from the human parasite entamoeba histolytica: a new drug target. | although there is a general agreement that the protist entamoeba histolytica lacks glutathione, it has been a matter of dispute as to whether this human parasite contains the glutathione derivative known as trypanothione. in the present study, we describe a gene for the tr (trypanothione reductase) obtained from e. histolytica by pcr amplification of its dna. after northern-blot analysis, the radiolabelled dna probe from trypanosoma cruzi hybridizes with the total rna of entamoeba, showing that ... | 2005 | 15157186 |
| proteinase inhibitors tpck and tlck prevent entamoeba histolytica induced disturbance of tight junctions and microvilli in enteric cell layers in vitro. | tight junctions and microvilli constitute an anti-invasive barrier at the luminal side of enteric cell layers. both subcellular structures are disrupted following adhesion of entamoeba histolytica trophozoites to enteric cell layers in vitro. it was our aim to analyse the molecular mechanism underlying this disruption. therefore, we cocultured enteric t84 cell layers established on filter inserts with e. histolytica trophozoites and tested various modulators of enteric molecules, involved in the ... | 2004 | 15157761 |
| amebiasis and comparison of microscopy to elisa technique in detection of entamoeba histolytica and entamoeba dispar. | the analysis of records of amoebal infection in various hospitals in kilimanjaro indicated frequent occurrence of amebiasis. the population over the age of five years had higher rate of amoebal infection compared to less than that of a five-year-old population; however, both age groups had similar patterns of amebiasis during january 1999 to june 2001. to investigate misdiagnosis of amebiasis, 226 patients (passive cases) in three hospitals and 616 individuals (active cases) from three different ... | 2004 | 15160983 |
| recognition of entamoeba histolytica 115-kda surface protein by human secretory immunoglobulin a antibodies from asymptomatic carriers. | entamoeba histolytica is a protozoan parasite that can invade the intestinal mucosa. infection induces production of secretory immunoglobulin a (siga) antibodies that can diminish the adhesion between e. histolytica trophozoites and epithelial cells in vitro and reduce the rate of new infections in children. siga antibodies produced by asymptomatic cyst carriers could play a protective role against the damage caused by e. histolytica. to identify membrane antigens capable of inducing siga respon ... | 2004 | 15165062 |
| entamoeba histolytica: induction of cyclooxygenase-2 expression during amoebic liver abscess formation in hamsters (mesocricetus auratus). | experimental amoebic liver abscess in hamsters curses with an increase in both, systemic levels of prostaglandin e2 (pge(2)) and local cyclooxygenase activity in liver microsomes. the cellular source of pge(2) and the isoform of cyclooxygenase responsible are not completely evidenced. cyclooxygenase-2 (cox-2) protein and gene expression were demonstrated on macrophages and polymorphonuclear cells as a result of entamoeba histolytica infection in hamsters at 2, 4, and 7 days postinfection by immu ... | 2004 | 15172219 |
| infection status of intestinal parasites in children living in residential institutions in metro manila, the philippines. | a small scale survey was performed to know the infection status of intestinal parasite in children of the residential institutions and street communities in metro manila, philippines. a total of 284 stool samples from 11 institutions and 3 street communities was examined by the formalin-ether concentration method. the scotch tape anal swab was adapted to 121 children to investigate the infection status of enterovius vermicularis. it was found out that 62.0% of the children examined were positive ... | 2004 | 15181346 |
| sequence divergence of entamoeba histolytica tubulin is responsible for its altered tertiary structure. | atypical microtubular structures of the protozoan parasite entamoeba histolytica (eh) have been attributed to amino acid sequence divergence of eh tubulin. to investigate if this sequence divergence leads to significant differences in the tertiary structure of the eh alphabeta-tubulin heterodimer, we have modeled alphabeta-tubulin heterodimer of eh based on the crystal structure of mammalian tubulin. the predicted 3d homology model exhibits an overall resemblance with the known crystal structure ... | 2004 | 15184082 |
| entamoeba histolytica gal/galnac lectin depletes antioxidant defences of target epithelial cells. | among the variety of virulence factors of entamoeba histolytica, an adherence lectin (gal/galnac, 260 kda) is known to mediate colonization and subsequent host responses. gal/galnac lectin is universally recognized by the immune sera of patients with amoebic liver abscess. it plays a crucial role in cytolysis and phagocytosis of human and rat colonic mucin glycoproteins. the objective of the present study was to elucidate the role of antioxidants in e. histolytica gal/galnac lectin-induced signa ... | 2004 | 15206463 |
| a single step duplex pcr to distinguish entamoeba histolytica from entamoeba dispar. | in this study, a single-step duplex polymerase chain reaction procedure was developed for rapid, specific and sensitive identification of entamoeba histolytica and for its diagnostic differentiation from e. dispar. specific oligonucleotide primers were combined for the amplification of a cysteine proteinase 5 gene target sequence of 242 bp, present only in e. histolytica. additionally, another oligonucleotide primer pair for both the e. histolytica and e. dispar actin gene target of 300 bp was d ... | 2004 | 15206464 |
| molecular and biochemical characterization of d-phosphoglycerate dehydrogenase from entamoeba histolytica. a unique enteric protozoan parasite that possesses both phosphorylated and nonphosphorylated serine metabolic pathways. | a putative phosphoglycerate dehydrogenase (pgdh), which catalyzes the oxidation of d-phosphoglycerate to 3-phosphohydroxypyruvate in the so-called phosphorylated serine metabolic pathway, from the enteric protozoan parasite entamoeba histolytica was characterized. the e. histolytica pgdh gene (ehpgdh) encodes a protein of 299 amino acids with a calculated molecular mass of 33.5 kda and an isoelectric point of 8.11. ehpgdh showed high homology to pgdh from bacteroides and another enteric protozoa ... | 2004 | 15206932 |
| entamoeba histolytica: ultrastructure of trophozoites recovered from experimental liver lesions. | ultrastructural studies on entamoeba histolytica have been carried out mostly with trophozoites cultured for many years. under these conditions, the availability of nutrients and the absence of environmental stimuli may switch off some phenotypic characteristics of the parasite. as a result, virulence of e. histolytica diminishes with prolonged culture passages, and the ability to form cysts disappears in axenically maintained trophozoites. the present analysis by transmission electron microscop ... | 2004 | 15208036 |
| identification of the entamoeba histolytica galactose-inhibitable lectin epitopes recognized by human immunoglobulin a antibodies following cure of amebic liver abscess. | immunity to entamoeba species intestinal infection is associated with the presence of intestinal iga antibodies against the parasite's galactose-inhibitable adherence lectin. we determined the epitope specificity of serum and intestinal antilectin iga antibodies by enzyme-linked immunosorbent assay using overlapping fragments of a recombinant portion of the lectin heavy subunit, designated lc3. these findings were correlated with the effects of epitope-specific murine antilectin immunoglobulin a ... | 2004 | 15213142 |
| enteropathogens associated with cases of gastroenteritis in a rural population in jordan. | stool specimens were collected from 180 patients belonging to a population of recently settled bedouins in jordan who presented with acute or persistent diarrhoea and other symptoms, and from 100 non-diarrhoeal controls. all samples were examined for parasites and bacterial pathogens by culture and pcr. bacterial isolates were tested for their susceptibility to common antimicrobial agents. pathogens and potential enteropathogens were identified from 140 (77.8%) of the patients, with more than on ... | 2004 | 15214876 |
| inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters. | we have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (aealah). in hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. focal liver ischemia, always present in control aealah wi ... | 2004 | 15215052 |
| resistance of entamoeba histolytica to the cysteine proteinase inhibitor e64 is associated with secretion of pro-enzymes and reduced pathogenicity. | cysteine proteinases (cps) have been considered suitable targets for the development of antiparasitic drugs. to assess the importance of cps for the growth and pathogenicity of the protozoan parasite entamoeba histolytica we have cultured amoebae in the presence of various cysteine proteinase inhibitors (cpis). it was found that broad range cpis, which are membrane permeable and rapidly enter the cell, are highly toxic at micromolar concentrations, and all attempts to generate e. histolytica mut ... | 2004 | 15215238 |
| overexpression of myosin ib in living entamoeba histolytica enhances cytoplasm viscosity and reduces phagocytosis. | the human parasite entamoeba histolytica is an ancient protozoan that expresses only one unconventional myosin, which has homology with myosin ib from other amoebae. myosin ib is involved in phagocytosis of human cells by e. histolytica. in this work, we developed a microrheological technique, analysing magnetic phagosomes, which allowed us to probe the density of the f-actin network in living cells. using this technique, we showed that overexpression of myosin ib led to an increase in cytoplasm ... | 2004 | 15226399 |
| protozoal infections in the developmentally disabled: often overlooked cause of rectal digging and fecal smearing. | | 2004 | 15226486 |
| overdiagnosis of amoebiasis in the absence of entamoeba histolytica among patients presenting with diarrhoea in wonji and akaki, ethiopia. | to confirm the high reported incidence of intestinal amoebiasis among study participants at 2 cohort sites in ethiopia where an hiv/aids study is taking place, stool samples of 232 patients with complaints of diarrhoea were examined for the presence of entamoeba histolytica and e. dispar dna between april and december 2001. by microscopy, 91 (39%) of the study participants were reported to harbour entamoeba trophozoites and/or four-nucleated cysts. using specific e. histolytica and e. dispar dna ... | 2003 | 15228248 |
| [the 'bull's eye' pattern in hepatic tomography]. | invasive fungal infections are more commonly found in patients who develop neutropenia after chemotherapy. a 4-year-old girl with diagnosis of acute lymphoid leukemia developed febrile neutropenia after chemotherapy. broad spectrum antibiotics and antimycotic therapy were initiated. candida albicans was isolated and entamoeba histolytica was observed in stool examination. chronic disseminated candidiasis had developed and was treated with amphotericin b, initially, and fluconazol. computed tomog ... | 2004 | 15239596 |
| detection and genotyping of entamoeba histolytica, entamoeba dispar, giardia lamblia, and cryptosporidium parvum by oligonucleotide microarray. | entamoeba histolytica, giardia lamblia, and cryptosporidium parvum are the most frequently identified protozoan parasites causing waterborne disease outbreaks. the morbidity and mortality associated with these intestinal parasitic infections warrant the development of rapid and accurate detection and genotyping methods to aid public health efforts aimed at preventing and controlling outbreaks. in this study, we describe the development of an oligonucleotide microarray capable of detecting and di ... | 2004 | 15243091 |
| identification of genomic responses to collagen binding by trophozoites of entamoeba histolytica. | attachment of entamoeba histolytica trophozoites to collagen is a known stimulus for parasite activation, leading to subsequent tissue destruction and invasion. to identify cellular mechanisms of trophozoite activation, we assessed global variations in gene expression during collagen interaction with e. histolytica. a shotgun dna microarray was constructed by use of 9600 random inserts from an e. histolytica genomic dna library. through differential hybridization, key differences between gene ex ... | 2004 | 15243916 |
| pyogenic and amebic liver abscesses. | pyogenic and amebic liver abscesses are the two most common hepatic abscesses. amebic abscesses are more common in areas where entamoeba histolytica is endemic, whereas pyogenic abscesses are more common in developed countries. pyogenic abscess severity is dependent on the bacterial source and the underlying condition of the patient. amebic liver abscess is more prevalent in individuals with suppressed cell-mediated immunity, men, and younger people. the right lobe of the liver is the most likel ... | 2004 | 15245694 |
| inhibition of gene expression with double strand rna interference in entamoeba histolytica. | in order to inhibit gene expression in entamoeba histolytica, we have developed a method based on expressing double strand rna interference constructs in stable transformants. the 5' end of eh dia was cloned head to head with an intervening non-specific stuffer fragment in the e. histolytica expression vector pjst4. this construct was transformed in e. histolytica hm1:imss trophozoites and stable transformants were selected with 20microg/ml g418. our results show that expression of eh dia was co ... | 2004 | 15249205 |
| histopathology of cutaneous amebiasis. | cutaneous amebiasis (ca) is the manifestation in the skin and underlying soft tissues of the pathogenic properties of entamoeba histolytica, which may be the only expression of the infection or may be associated with disease in other organs. so far, there have been only isolated case reports on this disease. we herein report the histopathologic findings on a series of seven cases, six adults and one child, of ca. the most common findings include ulcers, areas of necrosis, mixed inflammatory infi ... | 2004 | 15249857 |
| calcium binding protein 1 of the protozoan parasite entamoeba histolytica interacts with actin and is involved in cytoskeleton dynamics. | blocking expression of ehcabp1, a calmodulin-like, four ef-hand protein from the protozoan parasite entamoeba histolytica, resulted in inhibition of cellular proliferation. in this paper we report that ehcabp1 is involved in dynamic changes of the actin cytoskeleton. both endocytosis and phagocytosis were severely impaired in cells where ehcabp1 expression was blocked by inducible expression of the antisense rna. in wild-type cells both actin and ehcabp1 were found to co-localize in phagocytic c ... | 2004 | 15252130 |
| multiple parasite infections and their relationship to self-reported morbidity in a community of rural côte d'ivoire. | concomitant parasitic infections are common in the developing world, yet most studies focus on a single parasite in a narrow age group. we investigated the extent of polyparasitism and parasite associations, and related these findings to self-reported morbidity. | 2004 | 15256525 |
| enteric infection in relapse of inflammatory bowel disease: importance of microbiological examination of stool. | previous reports have suggested that diarrhoeal relapses of inflammatory bowel disease (ibd) may be associated or confused with enteric infection, and that treatment of such infections with appropriate antibiotics may be beneficial. to re-evaluate the suggestion that enteric infection is rare and microbiological testing of stool not routinely necessary in patients presenting with relapse of ibd, we have reviewed the incidence of concurrent infection in patients presenting in relapse over a recen ... | 2004 | 15256979 |
| evaluation of newer diagnostic methods for the detection and differentiation of entamoeba histolytica in an endemic area. | we evaluated the colorimetric polymerase chain reaction (pcr)-based method for the detection and differentiation of entamoeba spp. and compared the efficacy of e. histolytica-specific antigen detection in faeces with the detection of specific antibodies to e. histolytica-specific antigen in faeces, by enzyme-linked immunosorbent assay. faecal samples were obtained from patients attending hospital in chandigarh, india, from march 2001 to february 2002. the pcr-based colorimetric method was found ... | 2003 | 15259465 |
| energetics and mechanism of ca2+ displacement by lanthanides in a calcium binding protein. | the displacement of ca(2+) by trivalent lanthanide ions (tm(3+)) in a protozoan (entamoeba histolytica) ca(2+) binding protein has been studied by nmr and isothermal calorimetry (itc). the study provides a basis for understanding the behavior of lanthanides when used as a substitute for ca(2+), the pattern of sequential binding, the structural changes involved, the range and magnitude of paramagnetic interaction, and the associated energetics and mechanism. the progressive ca(2+) displacement fr ... | 2004 | 15260475 |
| cysteine proteinase activity is required for survival of the parasite in experimental acute amoebic liver abscesses in hamsters. | axenic trophozoites of entamoeba histolytica strain hm1-imss grown in vitro in the presence of e-64, a potent irreversible inhibitor of cysteine proteinases, preserved their viability, their rate of replication, their resistance to complement, their haemolytic capacity and their ability to destroy target cells, despite complete inhibition of total cysteine proteinase activity. on the other hand, their erythrophagocytic capacity and their ability to decrease ter of mdck cells was partially decrea ... | 2004 | 15267108 |
| amoebapores. | the enormous cytolytic potential of entamoeba histolytica appeals to parasitologists and immunologists because it kills target cells in a contact-dependent reaction resembling that of cytotoxic lymphocytes. in this review, matthias leippe summarizes what is currently known about a family of pore-forming peptides termed 'amoebapores', to which the cytolytic effect has been attributed, and describes the structural and functional properties of these potent factors, as well as their structure-activi ... | 1997 | 15275088 |
| survival strategies of entamoeba histolytica: modulation of cell-mediated immune responses. | tissue invasion and disease associated with the protozoan entamoeba histolytica has long been connected with suppression of host cellular immunity. dampening of the host's defences may facilitate survival of amoebae in extraintestinal sites and development of the characteristic amoebic abscesses. in recent years, several studies have begun to clarify, at the cellular level, the specific effects e. histolytica has on immune cell accessory and effector cell functions. here, darren campbell and kri ... | 1997 | 15275089 |
| the role of extracellular cysteine proteinases in pathogenesis of entamoeba histolytica invasion. | the extracellular cysteine proteinases of entamoeba histolytica have been implicated as important virulence factors in the pathogenesis of amebiasis and play a key role in tissue invasion and disruption of host defenses. these proteinases have attracted considerable interest as targets for novel therapeutic agents and as vaccine candidates. here, xuchu que and sharon reed highlight some of the more recent findings, focusing in particular on functional and structural features of the extracellular ... | 1997 | 15275090 |
| recent advances in dna-mediated gene transfer of entamoeba histolytica. | during the past few years, the introduction of dna-mediated gene transfer into parasite research has permitted subtle studies on fundamental aspects of parasite biology. in this paper, egbert tannich describes the recent breakthrough of successful entamoeba histolytica transfection, and the subsequent developments in this field. | 1996 | 15275214 |